Portable double-layer lunch box



FIG. 1 is a top, front perspective view of a portable double-layer lunch box showing my new design;

FIG. 2 is another top, front perspective view of the portable double-layer lunch box in FIG. 1 shown with the handle in a closed position thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a left side elevational view thereof; and,

FIG. 8 is a right side elevational view thereof.

The broken line shown in the figures depict portions of the portable double-layer lunch box that forms no part of the claimed design. In particular, the broken lines shown in FIG. 6 depict a boundary line and the broken lines and areas within depict portions of the portable double-layer lunch box form no part of the claimed design. 

CLAIM The ornamental design for a portable double-layer lunch box, as shown and described. 